Core barrel for oil well apparatus



Jan. 24, 1939.

w. FRENZEL GORE BARREL' FOR OIL WELL APPARATUS 2 Sheets-Sheet 1 Filed Jan. 30, 1936 A! 9 2 6 Z .fi/rwfl 4M l w WW 9 m o m fl {a ny 4 4 k 7 7 F J i mww a; O m 3 a 9 5 9 A, Z 4 5 Z oJ E 4 .i 4 A W a k ////////7/Z/////////////// 5 //////A///AZ//////////////////// 4 w A, 4 a 2 x z 5 J a Jan. 24, 1939. w. G. FRENZEL I CORE BARREL FOR OIL WELL APPARATUS.

Filed Jan. 30, 1936 2 Sheets-Sheet 2 Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE CORE BARREL FOR OIL WELL APPARATUS Wilbur G. Frenzel, Vidor, Ten, as'signor to Harry Pennington, San Antonio, Tex.

Application January 30, 1936, Serial No. 61,611

4 Claims.

This invention relates to the class of well drilling and pertains particularly to an improved method and device for taking a core sample.

In the present well drilling operations, the method employed for taking a sample of earth from the stratum through which the drill is passing requires the removal of the entire drill stem. Since these drill stems are usually several thousand feet in length, this necessitates the loss of many hours in the actual drilling operation.

The present invention has for its primary object "the provision of an improved method of taking a core from the well without necessitating the removal of the drill stem.

A further object of the invention is to provide an improved method of removing core samples by employing the mud which is normally circulated through the drill stem or about the stem in the process of drilling, to carry in the core taker and remove it from the well.

A still further object of the invention is to provide an improved core barrel which is designed to be introduced into the drill stem and automatically locked in place in the tubular drill at the lower end of the stem so that the desired core can be taken up into the barrel during the drilling operation.

Still another object is to provide a novel means of releasing the locked core barrel after the same has received a sample of the earth and of removing it from the well through the drill stem without the employment of pulling apparatus or other tackle.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:-

Figure 1A illustrates in longitudinal section a portion of the lower end of a drill stem showing in longitudinal section therein the upper part of the core barrel constituting part of the present invention.

Figure 1B illustrates in longitudinal section the lower end of a drill stem showing in longitudinal section therein the lower part of the core barrel, the lower end of the drill stem being modified for coaction with the core barrel.

Figure 2 is a view in side elevation of the core barrel and drill stem plug, the barrel being centrally broken.

Figure 3 is a view in longitudinal section through the lower part of the drill stem showing the core barrel holding dogs in released position.

Figure 4 is a section on the line 4-4 of Figure 1A.

Figure 5 is a section on the line 5-5 of Figure .1B.

Figure 6 is a section on the line 6--6 of Figure 1B.

Figure 7 is a section on the line 'I-1 of Figure 1B.

Figure 8 is a section on the line 8-8 of Figure 1B.

Figure 9 is a section on the line 9-9 of Figure 13- I Figure 10 illustratesv a drill stem body designed to divert the mud from the center of the drill bit through .the lateral passages thereof.

Referring now more particularly to the drawings, wherein like numerals of reference designate corresponding parts throughout the several views, the numeral 1 indicates generally a drill stem of tubular formation, at the lower end of which the interior diameter is reduced slightly, as indicated at 2, to form the terminal thickened portion 3 which, at its lower end, is provided with the threaded coupling screw 4. To this coupling screw is attached a bit carrying sleeve 5, the upper end of which is suitably recessed and threaded to receive the portion 4 of the stem while the lower end has the threaded extension 6 for connection with the tubular or hollow bit I. This bit I has a central outlet 8 which is surrounded by the blades 9 and which is of slightly less diameter than the bore or passage through the bit which alines with the passage through the coupling 5, thus forming an annular inte- H rior shoulder in upon the surface of which upstanding lugs H are formed and equidistantly spaced. These lugs may be in any number but are here illustrated as being four.

The bit I is provided with the usual mud channels or tubes I 2, as illustrated particularly in Figures 13, 8 and 9 which normally communicate with the interior of the stem l to receive the mud which is pumped down through the stem in the course of drilling so as to wash out the earth cut away by the bit or to permit this mud to pass upwardly through the bit from the bottom of the well after the mud is pumped down around the outside of the stem during the drilling operation. The wall of the stem l in 2 l 9,145,170 the constricted lower portion, together with the wall of the coupling or extension '5, is provided. with a pair, or more ii desired, of longitudinal grooves I 3 for the free passage of mud through the stem when the core sample taking barrel is in position therein as will be hereinafter more fully described.

The bit carrying'extension 5 is provided with the interior oppositely disposed recesses II which open into the passage or bore of the coupling and the coupling has two passages drilled transversely therethrough, as indicated at [5, each of which passes through the central part of and across a recess l4 and has a pivot pin l6 located therein. Upon each of the pivot pins I8 is oscillatably mounted a. dog ll having at its upper end an arcuate finger l8 which is upwardly and outwardly curved upon its inner surface or that surface which is directed toward the passage through the coupling. A pair of spring members, each of which is indicated by the numeral I9, is mounted in the body of the coupling in a suitable opening 20 and each is held in place by a screw 2| and presses at its inner end against the back of a dog finger l3 so that normally the points of the dogs II are moved apart and are out of the area defined'by the bore of the cou- The core barrel is indicated generally by the numeral 22 and consists of a main tubular body portion or barrel 23, a tubular cap 24 which is of a diameter to receive the barrel, and a ball valve carrying plug 25. The barrel or body porwhen the barrel is in position these lugs II will engage in the notches and operate to prevent the barrel turning.

At its upper end the barrel 23 is interiorly threaded to receive the lower end of the ball valve carrying body 25, which body is tubular and provided with a seat upon its upper end on which a valve ball 29 may rest. The upper end of the body 25 is enlarged to form the surrounding outwardly projecting collar 30 for the purpose hereinafter set forth.

The tubular cap 24 is formed in two units which comprises a lower sleeve portion 3| and an upper cage portion 32, the wall of which is provided .with the openings 33,, while the closed top has the longitudinally extending shouldered head 34. The two units 3| and 32 are threadably coupled together and the upper end of the unit 3| forms an interior shoulder 35 which is located beneath the collar 30 of the body 25 so that this shoulder which has a lower or bottom surface 36, has limited movement in the area between'the collar 30 and the top-end of the barrel 23in which the lower end of the body 25 is threadably engaged. Theupward movement of the cap 24 is limited by the engagement of the shoulder 35 against the underside of the collar 30, while its downward movement is limited by the engagement of-the lower surface 36 oi the shoulder with the top end of the barrel 23.

. The lower edge of the unit 3| is beveled upon its outer side, as indicated at 31, for engagement with the curved inner surfaces of the fingers l3 in the operation of the core barrel as will be 4 hereinafter explained.

The numeral 33 designates generally the stem plug which is used in association with the corebarrel. This plug comprises a cylindrical body 39 of soft or sponge rubber which is normally of a diameter greater than the interior diameter of the stem I so that when it is introduced-into the stem it-is substantially compressed and eflectively closes or seals the same. Extending'longitudinally through the body 39 is a bolt 40, the upper end of which has an eye 4|, while the lower end has thereon a nut 42 which bears against the lower end of the cylindrical body 33 and has'secured thereto the ends of short longitudinally extending spring arms 43. Each of these arms has attached to its lower end a hook member 44, the bill or nose of which extends inwardly and these hook members are so spaced that they may receive therebetween the narrow portion of the head 34 of the core barrel but must be sprung outwardly in order to pass over the wide top thereof sothat when they have once passed the top they will close in and firmly grip the head.

In the operation of the present device the same is introduced into the upper end of the drill stem without the plug pdrtion 38. The barrel is then forced downwardly by pumping mud into the stem behind the barrel so that it will be caused to move down into the reduced portion of the stem bore at its lower end and into the passages of the coupling 5 and the bit I. The engagement of the barrel in the passage 5 is relatively snug and, therefore, after the barrel is in position the mud which is pumped into the stem will pass along the grooves 13 in order to reach the outlet passages or bores l2 in the bit body.

The collar 25 which forms a part of the barrel passes between the dogs l1 and when the lower end of the barrel is at rest upon the shoulder Ill in the bit, the top surface 21 of the collar 26 will be just belowthe lower ends of the dogs so that they may be oscillated inwardly by the beveled lower edge 31 of the portion 24 and in positioning over the surface 21 will prevent upward movement of the-core barrel in the bit when the latter is operated. Naturally, in order that the dogs ll may be oscillated as described, the cap portion 24 of the barrel will bedown as far as it may go on the portion 23 thereof. With the core barrel fixed in this manner, the stem will then be actuated in the usual manner of-drilling until the bit has penetrated a sufiicient distance into the earth beyond the point it had reached when the core barrel was introduced, to fill the core barrel. During this operation, the valve ball 29 will shift sufilciently to permit mud and water to leave the barrel as the latter is filling with the earth through which the bit is passing. After the core barrel has been filled the drill stem plug 38 is introduced and is driven downwardly in the stem by pumping mud against it until the hooks 44 pass over and engage beneath the broad or wide top of the head 34.

Removal of the plug 38 with the core barrel and the sample therein is effected by pumping mud into the well between the well casing and the drill stem I so that the mud will pass upwardly through the bit passages I2 and the grooves I3 to the underside of the plug 33 and will force the latter upwardly in the drill stem. The first movement upwardly of the plug 38 will shift the top part or cap portion 24 of the core barrel before moving the lower part 23 and this will release the fingers l8 of the dogs 11, permitting the springs to oscillate the dogs so that the earth sample has been taken.

When it is desirable to sink the well deeper without taking a core, the passage through the drill bit may be closed by means of the plug body illustrated in Figure 10, which body is indicated generally by the numeral 45. This body is constructed like the core barrel 22 with the exception that it has a solid plug 46 instead of a tubular one closed at its top by a valve ball and the. upper end cap-like portion 41 is imperforate. In other respects, it is like the core barrel 22 in that it has a long lower tubular portion 48 surrounded by the collar 49 for the actuation of the latch elements I! and the cap-like upper portion which is divided into two parts, has the lower part 50 provided with the beveled bottom edge 5| to engage the cam like inner surfaces of the fingers l8 when it is in position in the drill stem, to hold the lower ends of the fingers H in engagement with the top of the collar 49. At its upper end, the. head 52 is formed to be engaged by the hooks 44 carried by the resilient plug 39 when this bit closing plugv is to be removed.

This bit closing plug is inserted into the drill stem to close the passage through the drill bit when it is desirable to sink the drill deeper without taking a core. Its sole purpose is to stop the flow of mud through the center of the bit and divert it into the channels through which it usually passes.

The eye or ring 4| at the top of the resilient plug is provided for a hook which may be used to support the plug and possibly the core barrel attached thereto, when the plug or the plug and core barrel are at the surface.

I claim:-

1. In well drilling apparatus including a tubular stem, a tubular coupling at the lower end of the stem, a bit connected with said coupling and having a passage therethrough, said passage at its lower end being reduced to form a shoulder, an elongated tubular body adapted to position in the. tubular coupling with its lower end in said passage and resting upon said shoulder, means preventing the rotation of thetubular body, a pair of spring actuated dogs in said tubular coupling, means carried by the tubular body for engagement by said dogs when the said body comes to rest upon said shoulder, means forming a movable part of the tubular body for actuating the dogs into engagement with the said body carrying means, and means coupled with the said movable part of the body for effecting the movement of the body upwardly through the stem, said last means when shifted in the stem effecting the movement first of the movable part only of the body to effect the disengagement of the dogs from said body.

2. Inwell drilling apparatus including a tubular stem, a tubular coupling at the lower end of the stem, a bit connected with said coupling and having a passage therethrough, said passage at itslower end being reduced to form a shoulder, an elongated tubular body adapted to position in the tubular coupling with its lower end in said passage and resting upon said shoulder, means preventing the rotation of the tubular body, a pair of spring actuated dogs in said tubular coupling, means carried by the tubular body for engagement by said dogs when the said body comes to rest upon said shoulder, means forming a movable part of the tubular body for actuating the dogs into engagement with the said body .carrying means, and a stem plugging body adapted to be forced downwardly in the stem and having means for grappling the upper end of the tubular body, said bit and tubular'coupling having fluid passageways facilitating the introduction of fluid under pressure to the underside of said plug, said plug in moving upwardly under the application of fluid pressure first shifting the movable part of the tubular body to effect the release of the body by said dogs.

3. In well drilling apparatus including a tubular stem, a tubular coupling at the lower end of the stem, a bit connected with a coupling and having a passage therethrough, shoulder forming means in said bit passage, a pair of spring pressed clogs oscillatably mounted in the coupling, a core receiving device comprising an elongated tubular body formed in two parts having relative longitudinal movement one upon the other, said tubular body being open at its lower end and adapted to rest on said shoulder and position in said tubular coupling, means facilitating the engagement of said dogs with the lower part of the body, a valved outlet at the upper end of the body, one of the movable parts of the body extending downwardly over the other and adapted to actuate said dogs into engaging position with the body, a plug member adapted to be forced into the tubular stem, resiliently supported hook elements carried by the plug body upon its lower end, means forming a part of the tubular body facilitating the connection ofthe hook elements therewith when the plug is forced downwardly in the stem behind the tubular body, and said parts having limited relative movement, the in-' ner one of the parts of the tubular body extending beyond the lower end of the outer one of the parts, a valve controlled outlet at the upper end of the tubular body, means connected with the upper end of the outer one of the parts of the tubular body facilitating the withdrawal of the tubular body through the stem, spring actuated oscillatable elements in the lower part of the stem, and means forming a part of the inner portion of said tubular body. for engagement by said latching'elements, said latching elements being of a character to be moved into engagement with said means against the tension of the actuating springs therefor by the lower end of the outer portion of the tubular body, the shifting of said outer portion upwardly effecting the release of the latching elements for the withdrawal of the tubular body.

WILIBUR G. FRENZEL. 

